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Abstract

We thank Dr Koelemay for his interest in our article and also for pointing out some relevant aspects of our study. Assessing the primary cause of ischemic colitis after aortic reconstructions is, as you also pointed out, not always an easy task, as it is multifactorial in origin. We tried to minimize potential confounders by excluding all patients but those with at least one patent hypogastric artery and without chronic colon disease or previous colon resection. Also, clinically relevant ischemic colitis is relatively rare, and differences between groups were (as demonstrated in the past) not large. Therefore, histology was our only possible end point, arguably not always clinically relevant, yet—as we believe—most sensitive for the purpose of the study. It is correct that the intention-to-treat analysis as well as the analysis of the subgroup with patent inferior mesenteric artery (IMA) did not yield significant differences between the groups. The reason for mainly discussing the subgroup with patent IMA is also quite apparent: An already occluded vessel cannot have any influence on outcome if ligated or not. We initially encompassed all patients into the analysis; however, it was an explicit demand by the reviewers and editors of the Journal of Vascular Surgery to mainly include patients with a patent IMA, and we do fully agree that the later patients are the relevant ones for final evaluation. A multivariate analysis was also performed but did not yield further insight into causes for postoperative ischemic colitis. When analyzing all 157 patients regarding risk factors, no different results were seen: age, sex and blood loss were the parameters differing between patients with and without ischemic colitis. We believe that this result is actually of great relevance as it demonstrates that we are mainly talking about a hemodynamic problem in open surgery and not—as frequently believed—an embolic one, also underlined by the occurrence of ischemic colitis in patients with an occluded IMA. Histologic results of all patients are listed in the first paragraph of the “Results” section. Finally, we do agree that our data do not fully support the suggestion to replant the IMA in older patients and in those with high intraoperative blood loss. Yet, the fact that we did not encounter a single complication, neither intraoperatively nor postoperatively, by replanting the IMA and that revascularization usually means increased perfusion pressure and thus optimizing critical flow justifies the suggestion. Even more so, as we could not produce final evidence against IMA replant in patients with at least one patent hypogastric artery, even though it did not prove to be beneficial in the whole study population or the subgroup of patients with patent IMA. Regarding “Replanting the inferior mesenteric artery during infrarenal aortic aneurysm repair: influence on postoperative colon ischemia”Journal of Vascular SurgeryVol. 44Issue 4PreviewI hoped to find good level 1 evidence in the first randomized trial on the influence of replanting the inferior mesenteric artery (IMA) or ligation during open (semi)elective AAA repair on postoperative colon ischemia in the study by Senekowitsch et al (J Vasc Surg 2006;43:689-94). However, after having read the article, I still don’t have an answer. Full-Text PDF Open Archive